WASHINGTON (AP) — Emboldened conservatives who forced House Republican leaders to push a stopgap spending bill that unravels President Barack Obama’s health care law are digging in for a long fight, determined to stop “Obamacare” before the first individual signs up in less than two weeks.

Just ask the two lawmakers — one a first-term businessman from North Carolina, the other a self-described “North Georgia country boy” elected just months after Obama signed the law — who spurred the rank and file to pressure the leadership on the tea party’s signature issue.

“Our resolve on this is unrelenting,” said Rep. Mark Meadows, whose letter in July to House Speaker John Boehner, R-Ohio, and Majority Leader Eric Cantor, R-Va., called for collaboration to “defund one of the largest grievances in our time” and attracted 79 Republicans.

Lobbied hard by outside conservative groups such as the Club for Growth, the Madison Project and the Senate Conservatives Fund, Republicans turned the letter into legislation sponsored by third-term Rep. Tom Graves, a 43-year-old from Ranger, Ga., who lists his high school loves as football, algebra and his Mohawk haircut.

More than 140 Republicans signed on to the bill to keep the government running and delay the health care law. On Wednesday, the House leadership signaled it had acquiesced to rank-and-file demands and set a vote for Friday on legislation to fund the government through Dec. 15 at existing levels while permanently defunding the health care law.

Meadows, Graves and other conservatives declined to discuss the likelihood that the Democratic-led Senate would reject their bill and dismissed talk that their actions would cause a politically debilitating government shutdown similar to the House Republican standoff with Democratic President Bill Clinton in 1995-96.

“This is not 1995. This is very different today,” Graves told reporters. “I suggest you interview the folks who come to our town halls and you see the hurt and the pain and the concern in their eyes. You’ll understand why we have the resolve and the constitution here to stand up for them.”

Republicans insist this is their last, best chance to stop the law. Although some provisions are fairly well-established, such as children remaining on their parents’ insurance plans until age 26, a crucial change goes into effect Oct. 1. That’s when millions of people without access to job-based health care will be able to enroll online through new state insurance markets for coverage effective at the start of next year.

“Sept. 30 is a critical day,” Meadows, 54, who traded a sandwich shop for real estate development, said in an interview. “All of us are united in understanding that once you start enrollment, it becomes a totally different dynamic even though they’re not receiving benefits. When somebody enrolls in something, they assume they will be getting them. That’s why the American people are expecting us to fight now, not delay the fight until next year some time.”

Republicans also contend that Senate Democrats from Republican-leaning states who voted for the law will switch sides as they look ahead to tough re-election bids next year. Politically, flip-flopping on such a high-profile vote could be devastating for an incumbent. Still, Republicans are looking forward to making several Democrats — Mark Pryor of Arkansas, Mark Begich of Alaska, Mary Landrieu of Louisiana and Kay Hagan of North Carolina — vote again with Obama on a law that opinion polls show remains confusing and unpopular.

Yet even proponents in the Senate acknowledge that their chances of defunding Obamacare are slim.

Sen. Ted Cruz, R-Texas, a chief sponsor in the Senate, acknowledged that Majority Leader Harry Reid, D-Nev., likely has the votes to remove the provision defunding the health care law and send back to the House a bill to keep the government operating.

Cruz said in a statement that House Republicans then must stand firm.

But other Republican senators dismiss the tactic as time-consuming and unrealistic. The fiscal year ends Sept. 30.

“It’s a political ploy,” said Sen. Tom Coburn, R-Okla., who says he opposes stopgap spending bills in general. “Tell me a bill that the president’s going to sign and figure out how we get there, and then I’ll support that.”

House Republicans refused to discuss hypotheticals about what the Senate might do to their bill. They insist that their approach gives the House leverage.

“You play offense,” said Rep. Chris Collins, R-N.Y. “We send them a solid plan that America is behind, then it’s up to the Senate and it’s up to the president to decide whether our plan makes sense or whether they want to draw a line in the sand and shut the government down.”